<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.5.2/jquery.min.js" type="text/javascript" ></script>
<script src="/js/gu.js" type="text/javascript" ></script>
<script src="/js/main.js" type="text/javascript" ></script>
<script>
function simpleAlert(){
	alert("we got a click, don't we ;) ");
}
</script>
<body>
<button onclick="simpleAlert();">Click</button>
</body>